A PRESSURE SENSITIVE ADHESIVE PRODUCT IS PRODUCED BY CASTING ON A SUBSTRATE WEB, SUCH AS PAPER, PLASTIC FILM, OR METAL FOIL, A LAYER OF AN ADMIXTURE CONSISTING ESSENTIALLY OF: (A) A DIENE POLYMER OR COPOLYMER HAVING AT LEAST 1.6 TERMINAL ACTIVE-HYDROGEN GROUPS AND AN EQUIVALENT WEIGHT OF 500 OR MORE, (B) AN ORGANIC POLYISOCYANATE AND 3 (C) AT LEAST 75 PARTS PER 100 PARTS OF THE DIENE POLYMER AND THE ORGANIC POLYISOCYANATE OF A TACKIFYING RESIN OR MIXTURE OF TACKIFYING RESINS HAVING A BALL AND RING SOFTENING POINT OF 60* TO 140*C. THAT HAS BEEN PREDISSOLVED IN THE DIENE POLYMER, AND COREACTING THE DIENE POLYMER AND THE ORGANIC POLYISOCYANATE IN SITU ON THE SUBSTRATE WEB TO GIVE A PRESSURE SENSITIVE ADHESIVE PRODUCT. THE DIENE POLYMER AND THE ORGANIC POLYISOCYANATE, PLUS ANY OTHER INGREDIENTS COREACTIVE WITH THE DIENE POLYMER AND THE ORGANIC POLYISOCYANATE THAT ARE USED, ARE CHOSEN SO THAT THE PRESSURE SENSITIVE ADHESIVE POLYMER FORMED ON THE SUBSTRATE WEB HAS THE CHARACTER OF AN ELASTOMER.